Boosted nitrilation of dimethyl adipate with NH3 to adiponitrile over bimetallic oxide: Synergetic effect between Nb and W

To reach highly active and selective gas-phase nitrilation of dimethyl adipate (DMA) with NH3, a series of NbxW10-x (x = 10, 9, 7, 5 and 0) composite were fabricated by a sol-gel method to approach the homogeneous combination of NbOx and WOx. As a result, the single-pass yield of adiponitrile (ADN) reached 85.2% over Nb9W1 under lower reaction temperature and lower NH3/DMA molar ratio. Consequently, the space-time yield (STY) of ADN over Nb9W1 was 1.7 similar to 30 times higher than that of previous catalysts. Mechanistic experiments demonstrated the activity strongly correlates the interaction between the carbonyl functionality and the composite. Further, a significant synergistic effect between W and Nb was disclosed, wherein the Nb-based domains account for activating DMA while the W-based domains mainly adsorb and activate NH3 feedstock.